Our 2015 MKZ didn't have THX when we bought it, and we were disappointed with the factory stereo. We added an Alpine Amp and replaced the door speakers. Now it sounds great, except when the Active Noise Control system kicks in.

ANC uses the stereo speakers to produce sound waves to counter - suppress - the engine sounds. It works very well until we added the additional power and bass producing ability to the factory stereo. What was an unnoticible dampening of the engine sounds is now a loud rumble (roar?) that kicks in and out as the engine revs up and down. And you can't turn it off, since ANC is active all the time, the car rumbles and roars all the time.

The solution (as found via Google) is to disable the ANC by unplugging the 3 Microphones in the MKZ.

If there is a way to adjust the ANC system, or tune it to compensate for the improved sound system, it would be great. Any suggestions?

You must now realize that replacing the OEM audio system without professional consultation was ill advised. I'm sure that the settings to the ANC system was performed at the factory and probably can't be changed.

Unplugging the microphones is probably the best solution. Too bad you're losing one of the best features of the car.